This invention relates to methods and apparatus for material handling, and more particularly, for agitating and/or dispensing materials in a predetermined manner.
In the manufacture of products, it is often necessary to dispense and sort items, such as components used in assemblies or subassemblies, in some ordered manner, such that those items can then be used in subsequent manufacturing processes. These items might be delivered into containers, onto a conveyor belt, or directly to another machine. In other applications, it may be desirable to dispense and sort bulk granular or particulate materials. For the purposes herein, such components or other materials are collectively referred to for simplicity purposes generally as xe2x80x9citems,xe2x80x9d xe2x80x9cproducts,xe2x80x9d or xe2x80x9cproduct.xe2x80x9d
In certain applications, it may be necessary to not only deliver items in batches of an approximate predetermined quantity, but also to orient those items as they are dispensed such that those items may be more easily manipulated by machines, such as perhaps robots, or by workers, for subsequent use. It may also be desirable to dispense the items into another feeding device, the first such dispensing device then essentially taking on the role of a pre-feeder. Further, if the items are of a mixed nature, for example having two or more different components in a batch, it may be necessary to differentiate and separate the items into groups of their own kind during the dispensing process.
Other problems may arise in dispensing items, particularly in a production environment. Such items may become entangled with one another, and thus frustrate dispensing of such items in a controlled manner. Also, depending on the product being dispensed, static electricity may build up such that the product clings to the hopper or other container in which the product is held. Moisture can also cause a problem with such product by increasing the likelihood of adhesion of the items in groups.
Further, mechanical agitation or vibration of the items, such as is found in certain conventional dispensing devices, could potentially damage delicate items prior to being dispensed for subsequent use.
A dispenser may also be used for dispensing parts or components for certain manufacturing processing steps, such as de-flashing, cleaning, drying, counting, visual inspection, random selection, testing, chemical treatment, painting, coating, labeling, recycling, crushing, etc.
Various material handling devices have been patented. U.S. Pat. No. 4,118,074, issued to Solt, discloses a pulsed air activated conveyor for transporting bulk material. U.S. Pat. No. 4,848,974, issued to Wayt, discloses a system for the fluidized conveyance of flat articles, such as lids or bottoms for cans. U.S. Pat. No. 4,182,586, issued to Lenhart also discloses an air operated material handler, wherein jets of air are used to separate and align bulk storage items such as containers. U.S. Pat. No. 4,578,001, issued to Ochs et al., discloses an air conveyor hopper having air nozzles positioned on a rotating feed disc for engaging and carrying items.
While the foregoing designs are known, there still exists a need for improved methods and apparatus to perform mixing and dispensing of product.
Teoh et al. In U.S. Pat. No. 6,116,822 discloses the use of a vertical jet of air into a plurality of parts in order to agitate the parts and break up their bridge over a dispensing aperture. This jet of air, however is not described, illustrated, nor configured to take advantage of Bernoulli""s principle by which the rapid motion of air might create a vacuum that could draw into the parts hopper a volume of air greater than that supplied by the jet itself. The closed nature of the connection between hopper and channel leading to the pick up location prohibit the free flow of ambient air necessary to effect such an amplification of air flow.
It is, therefore, an object of the present invention to provide a dispensing system for dispensing products.
Another object of the present invention is to provide a method of dispensing products.
Another object of the present invention is to provide a method and apparatus for detangling products.
Yet another object of the present invention is to provide a method and apparatus for orienting products.
A still further object of the present invention is to provide a method and apparatus for detangling and orienting products.
A further object of the present invention is to provide a method and apparatus for sorting products.
A still further object of the present invention is to provide a method and apparatus for mixing products.
Generally, the present invention includes a dispensing apparatus for dispensing items from a plurality of items and comprises a container having a support surface for supporting the plurality of items, the container having an upper portion and an opening in the upper portion for receiving the plurality of the items. The container also has an open passageway in a lower portion thereof for dispensing items from the container. At least one pressurized fluid outlet is provided for delivering a pulse of pressurized fluid through the open passageway into the container of sufficient pressure to lift the plurality of items above the support surface, and at least one guide surface is provided for directing at least one of the plurality of items through the open passageway subsequent to the delivery of the pulse of pressurized fluid.
More specifically, the present invention includes an apparatus and methods for dispensing and/or mixing a variety of products on a predetermined or automated basis. The system uses pressurized fluid and a controller such as a programmable logic controller (xe2x80x9cPLCxe2x80x9d), microprocessor, or the like, to mix and/or dispense product upon application of compressed fluid pulses to the product. Products are xe2x80x9cfluidizedxe2x80x9d by the pulse of compressed fluid provided to the hopper, the compressed fluid preferably being a compressed gas such as air, although other gases or fluids, and in particular, inert gases could be used, depending on the specific application.
The present invention allows for products such as small components, parts, or particles to be dispensed from a batch contained in a compartment or hopper. Such products may be. dispensed to containers, various types of conveyances, or other dispensers, feeders, magazines, cartridges, or another machine for further processing.
The pulse application of compressed air temporarily lifts and levitates the items in the hopper, while simultaneously blanketing them in the flow of air. Upon termination of the pulse, the items again drop, due to force of gravity, into the hopper, but due to the lifting and levitation of the items caused by the pulse, one or more items may be reoriented such that as the pulse flow ceases, such items are properly orientated to pass through a dispensing door or opening, such as a slot, in a lower portion of the hopper. The remaining items in the hopper, by their nature, may again become entangled or otherwise contact one another as they fall into place in the hopper after the pulse flow, such that such items bridge the dispensing slot to thereby prevent the remaining products from passing therethrough.
An analogous example of how the present invention operates is the shaking of the salt shaker in order to release salt on a food item. In certain instances, inverting the salt shaker will allow the flow of granular salt through tiny openings in the salt shaker. However, over time, the salt within the salt shaker may bridge the openings thereby preventing further flow of salt. This requires the salt shaker to again be either shaken, or reverted to its normal position and then reinverted in order to once again begin flow of the salt.
Products dispensed as a result of the pulse flow, or xe2x80x9cblast,xe2x80x9d are generally dispensed in a row which, if a conveyance such as a conveyor belt is used, could be oriented to be transverse to the direction of travel of the conveyor belt, or, in line with the conveyor belt travel to allow for a more continuous line of products to be provided on the conveyor belt.
Control may be maintained over the dispensing rate and distribution of products being dispensed and this allows for an approximate predetermined quantity of products to be dispensed with each pulse of pressurized fluid, in a manner which may be independent of actual pulse frequency.
The pulses can be programmed to be made infrequently, in a series of intermittent predetermined sequences, or continuously with the frequency of hundred, or perhaps a thousand or more, pulses per minute.
Further, the present invention can provide dispensing in synchronism with the movement and speed of other machines in response to signals of one or more sensors which may be provided on the present dispensing system, and, the system can be configured to dispense products and parts of similar shape and size oriented in a predetermined direction.
The objectives of this invention include providing a method and apparatus for mixing, untangling, orienting, separating, dispensing, and feeding items from a plurality of items to some receiving apparatus, mechanism, or container.
This application gives additional emphasis and makes additional claims to important aspects of the invention. Specifically, much of the effectiveness of this invention comes from it""s power to generate a vacuum that draws into the container, through the open passageway at the bottom of the container, significant volumes of pulsed fluid. The fluid brought in by vacuum is normally the main mover of the plurality of items. This use of pulsed vacuum to draw in pulsed fluid through the dispensing aperture is a distinguishing feature for this invention over the prior art.
The present invention includes an apparatus comprised of a container with a support surface, an opening in the upper portion for receiving items, a passageway in the lower portion for dispensing items, a guide surface to direct items into the passageway, a means for generating pulses of vacuum that draw pulses of air (or other fluid) into the container through the open passageway, and sufficient volume of available air outside the passageway and outside the container to fill the vacuum generated inside the container. The pulses of fluid serve to lift and separate items immediately above and around the passageway.
In many cases the items in the immediate area of the passageway and beyond are fluidized.
There is a natural tendency for items thus lifted and separated to xe2x80x9cflowxe2x80x9d out the passageway upon termination of the pulse, as the air forced in and expanded by the sudden vacuum is now released to collapse and return to the lower pressure area created outside the container by the abrupt departure of the air from outside the container to the inside. This means that items inside the container might exit faster than if they were dependent upon gravity alone. The retreating air is forcing them along. It also means the items are less likely to immediately re-jam since the natural vacuums created by the moving fluid tend to align the items with the path the air takes upon it""s retreat out the passageway. There is also a tendency for items thus buffered with air to be better protected from damage than if vibration or other direct contact with some more rigid impetus moved them.
This application describes a variety of means to generate pulses of vacuum that in turn draw pulses of air (or other fluid) into the container through the passageway. These include the use of pulses of pressurized air into the container through the passageway, near the open passageway and in a second container, which extends into the lower portion of the primary container as well as other approaches. The use of thin sheets of pressurized air as provided by air knives and the use of laminar flow of air against supporting surfaces and guide surfaces further enhance the effectiveness of these pulses. When using vacuum pulses farther removed from the passageway it becomes important, during those pulses; to close the top opening in the container designed for supplying items. Otherwise, the power of the vacuum to draw air in through the passageway at the bottom of the container could be greatly diminished.
The invention teaches varying the size of the passageway. This can be especially helpful when dealing with more than a single configuration of items over time.
The invention teaches the inclusion of another container within the main container. Such a container can be used to block the area directly above the passageway from a large portion of the items in the main container. This can reduce the pressure on the items immediately above the passageway. This in turn reduces the necessary volume of air and level of pressure required to achieve satisfactory lift and separation of items to be dispensed at any given time. Such a container may also be configured to supply pulses of vacuum in the immediate area of the passageway.
The invention teaches the associated use of means to orient items to be dispensed and the associated use of means to separate various configurations of items.
The invention teaches the use of air funnels to enhance the effect of pulses of vacuum for moving the maximum volume of air into the container through the passageway.